var drawerMenu = {
	inc : 5,
	elements : new Array,
	timers : new Array,
	construct : function()
	{
		var dls = document.getElementsByTagName('dl');
		var n = 0;
		for(var i = 0; i < dls.length; i++)
		{
			if(dls[i].className == 'menu')
			{
				n++;
				drawerMenu.timers[n] = 0;
				dls[i].onmouseover = drawerMenu.triggerShow;
				dls[i].onmouseout = drawerMenu.triggerHide;
				dls[i].targetElement = n;
				for(var j = 0; j < dls[i].childNodes.length; j++)
				{
					if(dls[i].childNodes[j].nodeType == 1)
					{
						if(dls[i].childNodes[j].tagName == 'DD')
						{
							dls[i].childNodes[j].style.position = 'relative';
							dls[i].childNodes[j].style.overflow = 'hidden';
							dls[i].childNodes[j].style.height = '0px';
							for(var k = 0; k < dls[i].childNodes[j].childNodes.length; k++)
							{
								if(dls[i].childNodes[j].childNodes[k].nodeType == 1)
								{
									if(dls[i].childNodes[j].childNodes[k].tagName == 'UL')
									{
										drawerMenu.elements[n] = dls[i].childNodes[j].childNodes[k];
										dls[i].childNodes[j].childNodes[k].style.position = 'absolute';
										dls[i].childNodes[j].childNodes[k].style.top = '-'+dls[i].childNodes[j].childNodes[k].offsetHeight+'px';
									}
								}
							}
						}
					}
				}
			}
		}
	},
	triggerShow : function()
	{
		if(drawerMenu.timers[this.targetElement]) clearInterval(drawerMenu.timers[this.targetElement]);
		drawerMenu.timers[this.targetElement] = setInterval('drawerMenu.show('+this.targetElement+')', 20);
	},
	triggerHide : function()
	{
		if(drawerMenu.timers[this.targetElement]) clearInterval(drawerMenu.timers[this.targetElement]);
		drawerMenu.timers[this.targetElement] = setInterval('drawerMenu.hide('+this.targetElement+')', 20);
	},
	show : function(i)
	{
		var ul = drawerMenu.elements[i];
		var t = parseInt(ul.style.top);
		var inx = Math.ceil(-t/drawerMenu.inc);
		if(t+inx < 0)
		{
			ul.style.top = (t+inx) +'px';
			ul.parentNode.style.height = (ul.offsetHeight+t+inx) + 'px';
		}
		else if(t < 0)
		{
			ul.style.top = '0px';
			ul.parentNode.style.height = ul.offsetHeight + 'px';
		}
		else
		{
			clearInterval(drawerMenu.timers[i]);
			drawerMenu.timers[i] = 0;
		}
	},
	hide : function(i)
	{
		var ul = drawerMenu.elements[i];
		var t = parseInt(ul.style.top);
		var inx = Math.ceil(t/drawerMenu.inc);
		if(inx == 0) inx = -1;
		if(t+inx > -ul.offsetHeight)
		{
			ul.style.top = (t+inx) +'px';
			ul.parentNode.style.height = (ul.offsetHeight+t+inx) + 'px';
		}
		else if(t > -ul.offsetHeight)
		{
			ul.style.top = -ul.offsetHeight + 'px';
			ul.parentNode.style.height = '0px';
		}
		else
		{
			clearInterval(drawerMenu.timers[i]);
			drawerMenu.timers[i] = 0;
		}
	}
}

window.onload = drawerMenu.construct;